This application is related to and claims priority from Japanese Patent Application No. Hei. 10-246206 filed on Aug. 31, 1998, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a plate-fin type heat exchanger having plural tubes and plural fins, which can be suitably used as a radiator for cooling a cooling liquid of an internal combustion engine.
2. Description of Related Art
In a conventional plate-fin type heat exchanger, both ends (hereinafter, referred to as xe2x80x9clongitudinal endsxe2x80x9d) of each plate fin in a longitudinal direction of the plate fins have recesses for setting attachment positions of the plate fins when the plate fins are laminated. The recesses are simply provided only for setting the attachment positions, so that each plate fin simply extends from a tube adjacent to a longitudinal end of the plate fin toward the longitudinal end. Therefore, an entire area of each plate fin cannot be effectively used for improving heat-exchanging capacity of the heat exchanger.
In view of the foregoing problems, it is an object of the present invention to provide a plate-fin type heat exchanger having plural tubes and plural plate fins, in which an entire area of each plate fin can be effectively used for improving heat-exchanging efficiency.
According to present invention, a heat exchanger includes a plurality of plate fins laminated from each other in a lamination direction to have a predetermined clearance between adjacent plate fins, and a plurality of tubes penetrating through the plate fins in the lamination direction. Each of the plate fins has a recess portion for setting an attachment position when the plate fins are assembled, and the recess portion is provided at an end side of each plate fin in a longitudinal direction of the plate fins. A standing wall protruding in the laminating direction is formed on an outer periphery of the recess portion. Thus, air passing through the plate fins is disturbed by the standing wall of the recess portion, thereby preventing a thermal boundary layer from being enlarged. As a result, heat-transmission efficiency is improved, and heat-exchanging capacity is also improved. Further, because the standing wall is formed, flexural rigidity and torsional strength of each plate fin can be improved. Therefore, it can restricted plate fins from being deformed when the plate fins are assembled, and the plate fins can be accurately fixed at predetermined positions. That is, in the present invention, attachment positions of the plate fins can be accurately set by the recess portion when the heat exchanger is manufactured. Further, after the heat exchanger is manufactured, heat transmission efficiency can be improved by the standing wall of the recess portion so that an entire area of each plate fin can be effectively used for improving heat-exchanging efficiency.
Preferably, the standing wall of the recess portion has a wall surface on which air passing through between the plate fins is crossed. Therefore, air passing through the plate fins can be sufficiently disturbed by the standing wall of the recess portion.
More preferably, the standing wall is provided integrally with each plate fin by plastically deforming a part of each plate fin. Therefore, the standing wall of the recess portion is readily formed.